1. Field of the Invention
The invention relates to a latch mechanism and more particularly to a latch mechanism for the door of an appliance or the like adapted to actuate a door safety switch for the appliance when the door is fully closed and latched.
2. Brief Description of the Prior Art
The latch mechanism of the present invention may have many applications. While not necessarily so limited, the latch mechanism is particularly adapted for use with appliances of the type having a cabinet with a chamber and a door for closing the chamber. The latch mechanism may also be used to actuate a door safety switch, i.e. an appliance enabling switch, so that the appliance may perform its functions only when its door is firmly closed and latched. Exemplary applications of the latch mechanism of the present invention include cooking ovens, microwave cooking ovens, clothes washing machines and the like. For purposes of an exemplary showing, the latch mechanism will be described in association with an under-counter dishwashing machine.
The typical under-counter dishwashing machine has a cabinet with a vat or tub located beneath a sink or countertop. A front opening door is provided for the vat, the bottom edge of the door being hinged to the dishwasher cabinet and the door being swingable between a vertical closed position and a horizontal open position. The latch mechanism of the present invention provides a means whereby the door may be opened and closed and latched securely in a closed position. When in its closed and latched position, the bolt of the latch mechanism may be used to actuate a door safety switch to initiate, or permit initiation of, the dishwashing cycle.
Prior art workers have devised numerous types of latch mechanisms for appliances, some of which have safety switches in association therewith. United States Letters Patent 3,323,822 illustrates an exemplary prior art latch of this type. In accordance with the teachings of this patent, inadvertent actuation of the safety switch, when the door is not fully closed and latched, is avoided by the provision of a special trip means preventing the latch itself from being shifted to its closed position until the door is moved into a predetermined spaced relationship with a tub mounted strike. When the door is properly closed and latched, a portion of the latch lever itself actuates the door safety switch.
The present invention is based upon the discovery that a portion of the bolt itself may be used to actuate the door safety switch when the bolt is in its closed and latching position. This enables further simplification of the latch mechanism, eliminating the necessity for trip means and the like. The latch mechanism is sturdy, less expensive to manufacture and easier to operate. Despite its simplicity, the latch mechanism of the present invention may be so designed as to provide a mechanical advantage to assist in pulling the appliance door to its fully closed position.